AFM methods for studying the morphology and micromechanical properties of the membrane of human buccal epithelium cell

• Published in: Scientific reports Vol. 13; no. 1; p. 10917
• Main Authors: Torkhov, N. A., Buchelnikova, V. A., Mosunov, A. A., Ivonin, I. V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.07.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/57; 631/80; Adhesives; Adult; Biomechanical Phenomena; Cells; Cytology; Deformation; Elastic Modulus; Elasticity; Epithelium; Humanities and Social Sciences; Humans; Mechanical Phenomena; Mechanical properties; Membranes; Microscopy; Morphology; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-33881-x

Using AFM methods in air under normal conditions in a wide range of local force effects ( F const < 40 μN) the relief, functional micromechanical properties (elasticity coefficient K , Young’s modulus E , elastic Δ h dfrm and plastic Δ h stiff deformations) and adhesive properties (work A of adhesive forces F adh = F adh ( x ; y ) ) of the membranes of living adult cells of human buccal epithelium were studied in the presence of a protective layer < 100 nm of buffer solution that prevented the cells from drying. Almost all geometric and functional characteristics of the membrane in the local approximation at the micro- and nanolevels are affected by size effects and obey the laws of fractal geometry. The Brownian multifractal relief of the membrane is characterized by dimension D f < 2.56 and irregularities < 500 nm vertically and < 2 μm horizontally. Its response to elastic (≤ 6 nN ), active (6–21 nN), or passive (> 21 nN) stimulation ( F const ) is a non-trivial selective process and exhibits a correspondingly elastic ( K = 67.4 N/m), active ( K = 80.2 N/m) and passive ( K = 84.5 N/m) responses. K = K ( F const ) and E = E ( F const ) depend on F const . Having undergone slight plastic deformations Δ h stiff < 300 nm, the membrane is capable of restoring its shape. We mapped ( E = E ( x ; y ) , D f = 2.56; Δ h dfrm = Δ h dfrm ( x ; y ) , D f = 2.68; Δ h stiff = Δ h stiff ( x ; y ) , D f = 2.42, A = A x ; y and F adh = F adh ( x ; y ) ) indicating its complex cavernous structure.